The Greek word “apnea” literally means “without breath.” People with untreated sleep apnea stop breathing repeatedly during their sleep, sometimes hundreds of times during the night and often for a minute or longer.
Obstructive sleep apnea (OSA) is the most common category of sleep-disordered breathing. The muscle tone of the body ordinarily relaxes during sleep. At the level of the throat, the human airway is composed of collapsible walls of soft tissue which can obstruct breathing during sleep. Mild, occasional sleep apnea, such as many people experience during an upper respiratory infection may not be important, but chronic, severe obstructive sleep apnea requires treatment to prevent sleep deprivation and other complications.
Individuals with low muscle tone and abundant soft tissue around the airway (e.g., due to obesity), and/or structural features that give rise to a narrowed airway are at high risk for obstructive sleep apnea. The elderly are more likely to have OSA than young people. Men are more typical sleep apnea sufferers than women and children, although it is not uncommon in the latter two.
Common symptoms include loud snoring, restless sleep, and sleepiness during the daytime. Diagnostic tests include home oximetry or polysomnography in a sleep clinic.
Sleep apnea is very common, as common as adult diabetes, and affects more than twelve million Americans, according to the National Institutes of Health. Untreated, sleep apnea can cause high blood pressure and other cardiovascular disease, memory problems, weight gain, impotency, and headaches. Moreover, untreated sleep apnea may be responsible for job impairment and motor vehicle crashes.
Some treatments involve lifestyle changes, such as avoiding alcohol or muscle relaxants, losing weight, and quitting smoking. Many people benefit from sleeping at a 30 degree elevation of the upper body or higher, as if in a recliner. Doing so helps prevent the gravitational collapse of the airway. Lateral positions (sleeping on a side), as opposed to supine positions (sleeping on the back), are also recommended as a treatment for sleep apnea, largely because the gravitational component is smaller in the lateral position. Some people benefit from various kinds of oral appliances to keep the airway open during sleep. There are also surgical procedures to remove and tighten tissue and widen the airway, but these tend to be very intrusive. “Breathing machines” like continuous positive airway pressure (CPAP) may help.
The CPAP machine delivers a stream of compressed air via a hose to a nasal pillow, nose mask or full-face mask, splinting the airway (keeping it open under air pressure) so that unobstructed breathing becomes possible, reducing and/or preventing apneas and hypopneas. This has the additional benefit of reducing or eliminating the extremely loud snoring that sometimes accompanies sleep apnea. Prospective CPAP candidates are often reluctant to use this therapy, since the nose mask and hose to the machine look uncomfortable and clumsy, and the airflow required for some patients can be vigorous. Some patients will develop nasal congestion while others may experience rhinitis or a runny nose. Other conditions that can accompany the use of CPAP include flatulence caused by swallowing too much air; irritation of the skin due to wearing a CPAP mask; upper airway infection; red eye and tear flow; anxiety and feelings of suffocation and/or claustrophobia; and the need to cart around CPAP equipment during travel. Compliance requires self-discipline and resolve. Some patients adjust to the treatment within a few weeks, others struggle for longer periods, and many discontinue treatment entirely.